1. Field of the Invention
This invention relates generally to the dissipation of heat from high power electronic devices, and more particularly to a substrate carrier situated between a substrate supporting the high power electronic devices and a heat sink.
2. Description of Related Art
Systems utilizing electronic devices such as high power transistors encounter an ever-present problem of thermal management, that is, designing structures which are capable of efficiently conducting the heat generated by these devices, away from the substrates upon which they are mounted and the electronic packaging within which they are located. Furthermore, where such systems, such as radar systems, are located in high speed aircraft, weight introduces an added design problem.
Currently, high power communications and radar transmitters are utilizing heat generating semiconductor devices implemented in silicon carbide as well as silicon and gallium arsenide. These devices, moreover, are mounted on ceramic type substrates comprised of materials which attempt to match its coefficient of thermal expansion to that of an adjoining heat dissipating element, such as a cold plate, so that fracture and catastrophic failures due to uneven expansion due to heat are reduced. This has resulted in the use of some type of substrate carrier located between the substrate and the cold plate, and where the coefficient of thermal expansion of the carrier is tailored to match that of the substrate to prevent dimensional instability tending to cause device failure as a result of different degrees of expansion during operation in a relatively high thermal environment.